OKLAHOMA CITY -- Oklahoma didn't bring its best to its NCAA tournament opener at Chesapeake Energy Arena.

Thankfully for the Sooners, All-American guard Buddy Hield did.

That proved to be enough as second-seeded Oklahoma overcame an otherwise uninspiring performance Friday to defeat No. 15 Cal State Bakersfield 82-68.

The Sooners went just 15-of-25 from the free throw line. They got outrebounded 35-31 by an opponent that starts only one player taller than 6-foot-4. And at times they completely fell asleep defensively, leading to several easy Bakersfield layups.

But whenever Oklahoma needed a run or a basket to keep the Roadrunners from seriously threatening, Hield -- as he has all season -- delivered.

Once Bakersfield had clawed back into the game early in the second half, Hield countered emphatically, collecting a steal before pulling up for a 3-pointer. Moments later, Hield drove the lane, then kicked out to Dante Buford for another wide-open 3-point connection, putting the Sooners back up 52-46.

Bakersfield center Aly Ahmed had curiously declared the day before the game that Oklahoma was a "good but not great" team and was "beatable." The Sooners did look that way through large portions of the game, as Ahmed (16 points) and the Roadrunners manufactured enough buckets in the paint by capitalizing off several Oklahoma defensive lapses to hang around.

But when it mattered most, Bakersfield couldn't match up with Hield.

He had a game-high 27 points, but not before delivering the 3-point dagger with 2:27 remaining that put the Sooners up by double-digits again while finally putting the Roadrunners away for good.